#define _CRT_SECURE_NO_WARNINGS 1


#include<stdio.h>


int Findsingle(int arr[], int n)
{
	int a = 0;
	for (int i = 0; i < n; ++i)
	{
		a = a ^ arr[i];
	}
	return a;
}


int main()
{
	int arr[9] = { 1,2,3,4,5,1,2,3,4 };
	printf("%d\n",Findsingle(arr, 9));

	return 0;
}